1. Field of the Invention
The present invention relates to an oscillator circuit using an inverter loop with a delay element. The oscillator circuit of the present invention can be used, for example, as one of the elements of a substrate bias voltage generator provided in a semiconductor memory device.
2. Description of the Related Art
Generally known as an oscillator including an odd number of inverters cascade-connected in a loop and a delay circuit consisting of a capacitor and resistor inserted between adjacent inverters. In this oscillator, charging and discharging of the capacitor in the delay circuit cannot be fully effected. Therefore, the oscillating frequency of the oscillator cannot be made lower than a certain value unless a large value capacitor is used. Furthermore, the oscillating frequency of the oscillator is not stable vis-a-vis ambient temperature.